SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b74fb0addd778fa08725d5cad18ae6deadd088decbb4836430e6a9805eb64167' 
  AND token = 'idmkqiHPTmYoDQzM1qGJruxkexcQWpvfr+/MB4JLbHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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