SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '650cdf85b5deaeb7919e7cd3a3190f622ebb4c101d6c19798dfb0573a7ea5d2a' 
  AND token = 'xxihTzJw9PydrnUJXRd0O9fkbcXyrcBTbTyq9MRZ+eg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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