SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aaad8c48dd67cba1d0eb0a1813a19bf73b2c5071d2e951fe37ef2e280958577' 
  AND token = 'KLcrZKuC+QZ8f5/v+3d4Kwimb250PxqhzGbBlh2qRMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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