SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eba5de3e95a4bdd3601ed2324cb1cd09ee94638f3feab3989531268adf018300' 
  AND token = 'Ac7FhIXW0ENInU6IQCSPhFgzotlH44n7nLKvKZmQumE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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