SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a58d573230369e87f446428eb7c02902ff74c8165f58c6b451f181cab7b97246' 
  AND token = 'u3CooJvKht4nfvzWAv7OzzBWdGWNYZXPJHE5xphy4K8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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