SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7bffa8a818c10989408f52a2cbc23dd5b867c0403f520d3aacdb6f16bbd3599' 
  AND token = 'VKsZeEltLI0LpMQwwrDxy52tBm4GyiZjvaCkf/gSqks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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