SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1eb0da8e700f9a16feaf9d749a103a1259aefa0b11eea038b20e58b441047a7a' 
  AND token = 'IRenEv2mhNkzz3Q9cP8PJOSpBozbYBamNxZZjlnMUEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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