SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e74f85b3c5279883438e490a6a9491ff57f8d0e8e53f5546fa7dde4fbf893dd8' 
  AND token = 'hLfh87wVftl2wClwz2XZIITZZGlAtBxpq8gcHJnf9jI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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