SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5572af0c3d07e9a9cc37ca6307428842878971bfcfdb3e645031aa672bd6ce36' 
  AND token = 'kBA+uX+4S5E9EEXN05q2wWVxbPcOxAVg1wG/tzEKYBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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