SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d5641217b2471fef57177a8baf6dfc81461790fb4f74fcb7098e7e3cd491747' 
  AND token = 'Nj3+wZSiog8/eMAknmLn6Ne6vdG0w3M+FowJUMe9N2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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