SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9570e523aaf86a1277df44ec15d0d2571f286ddc54ff993690373c0a6c7a8f6' 
  AND token = 'SWc/r0Tsh9qI/dhz/BwP7V1RilNtTr4XJ/w3PLGNzZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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