SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cca4620d3b3fbbd99802b52ef169c358fc6ed31ce931e7d70594c3df91df93d' 
  AND token = 'L30jt1wYkMo0gCy+jKJCXrwNm/RU2kp0N21mD0ZQqLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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