SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8d9f2c0420f6bfac83510790f7c18274c2b685446f958625447f3269980d496' 
  AND token = 'zRLfY7VCL+mcQqf7Q0EB0XOvpdgmJIe5siZT11V9RwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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