SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b288214e0c77a76bcc3d678b6a16143a376796ad8d4e5625b2f2a92a493e340a' 
  AND token = 'noJULmCNc7dJmG1fvOVghGCU6PfB52CX/al7Z431KwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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