SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c843eb4fe2d4620f4a5704968869e0ff051380c79e8201de6e867b3be8a2568' 
  AND token = 'iRQDojyZ2rB4MxEbQ4j8Slb3r/Vv6JVyrX5jeCVUsyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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