SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bdcd72b44b24d8a17b381510428e8685f822cb7fbee869958b94a3bd52aceb4' 
  AND token = 'x0PqFXcyUA7naC7QiZ56t1TRDbzdI92YllJQB9cRkbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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