SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da88ac1e008db6a3da5fe89ae76c58a3017445193f5ea9c3493a5cb6ab774601' 
  AND token = 'PIoqcJm4BpBVn2rGeF1w5oddrZd5plrWLBRryJNtV90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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