SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66e27cfa6ad3491a8939cdb54c25f626f15fb9508c294c59691a645b02b541ee' 
  AND token = 'UEfk4fqZ8kEOlN+bAOmi2a9x6qKSZGxiXnQvSbtjhjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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