SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '531031232c5ff783a7c3c21416cb26d6879f84aa881e94028ceab1cef06c2070' 
  AND token = 'zaVCOI7LdioOrcDCgIJZBhnrUBoSuasAuUUsMl2BlNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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