SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dc309bdd981efc000d823df759c8a07f3b80001c48e635649751db99948629a' 
  AND token = 'M/rACLOc/zgFQC9ojgAwGQDHXl/A67xk9cSviMNvN10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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