SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '726e5a63e153da94cf2479c97b702b86401241138a47c58cfd3dcca7ddf77d19' 
  AND token = 'jbXsgXDiaQcSRqqtlZ/3dfJg2GPhGYLnm88jfbcxrEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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