Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6b92abac2b5e91e1d7f6e7a301c3dd5c97df7924fe897fe1473b1ff1a83e3bb' 
  AND token = '5d3GycB9J3a4tAtzfrn+9ft6YQnCTiZkdk7IYRn2Rw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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