SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43adb57194dc91d0b1788a39b5f177393fca0e6494a4e748f79af78dabb197cf' 
  AND token = '5EQP6qQRO3pxi3XsXWReCLQEOwYvtpjB6UHbZnHIwkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}