SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fac7c3fc95e13bc8a690de60d8d68275d6e3317d041daeec41c72fcf6c98b544' 
  AND token = 'JRRd4hQANotEe9VNVqEw/FvxU6imY5LHAhI4qeyQs4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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