SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f196650d2c4cc048b129d99592ee2c6e9a1abfcc1c04fcec3f0014fd3e081219' 
  AND token = 'iSXvlednS4Y5PqRairQhtMUD/ST5OQfj/nY2+qPwIDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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