SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d3e118803c8f1b814d11616bd9f89421c097fc89d528a1cd24df2eeff46ad2f' 
  AND token = 'kQ7h78FcKmG+ZlPBTSEUlTNkVs9cadlSun5cFTnYR8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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