SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bcd60cffe5098b22d9c59d39c2343205d7fe000bd6af4aef8666e24e512e02b' 
  AND token = 'uMz2y8L51SToVHODFb4NQ1Vw1/rvx0z1Oifuv4wGP2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}