SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94e113ba282b7ec71df317fe2fcf6fc07225f5922d12b44a0560de3f8718ac89' 
  AND token = 'ZszLlpOCeOSqJAKByFXLoF7FBZfsmuT+FdWH+kzKUNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}