SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfece39324e8e4a65dde9ec9be41ee1d098348966837ffceefa67589e5942746' 
  AND token = 'Bt/d6Gw4vcwuzS7R9wYe++kI2ZglLLghevgh0KvywgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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