SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0a5645d84332e3e8c5567ef7ee791249a3f3e6f4c704d0d2fc35b0d33693dae' 
  AND token = 'GW8Hpdl9QKqEA73oEgNIk51pesoL+fOd556Rk+X+Xrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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