SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c372d65849d2106947b313adda1824d10d193ba20a71e6283d0553015d10e5dd' 
  AND token = 'qcWXojQMao9xsSeoC4WUgddFAgGqn8P4MVoFOZS5eLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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