SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b457017d06e7eed78d3824e2d83c8554553e38623278ed5787392a6b2a91f864' 
  AND token = 'REoSHz9EAKqX0dUHjcNZ71X1HNJnxk1hRRTHZK1adys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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