SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f4f023d59fe85a476dd81ff690799660f15d63a88cccacaac9e021bce269717' 
  AND token = 'TCng1mE43J41nBp0BFXyQJuX/jhg33Tj5GtfyPV9FBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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