SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49bb67e884c53bfc76b036865945a9cf7f21642bfd13c222b53e12a0ea5936cd' 
  AND token = 'LCzwQEDM56EB3ta7AarbhPuNyipbu490QA/MpqSaTH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}