SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25bf3498f7656a0db81bdb4d6f56431f4f796c1036878706d6b6191e9deda8f1' 
  AND token = 'F5fqImN9egjCPWmWh6zJrbTNJKjpipYwQ6fpBB5nxfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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