SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4407258cd2370ebd31321df2cd8af9d4166d7e8811741aad570fe68ea35fc8d4' 
  AND token = 'ZKQAtxVp+fhbPblOGUAaAbUGeqYWxipJy2mxJRZ7YwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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