SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c74c7528b1bc114bb63441e8e7f85e5f32333e5c63d7c62a871f2b9c95251aa4' 
  AND token = 'pOCZm7lKvMdquA5aHlQWBAApwpD66jvExIL9hsnhaDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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