SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '772fea2e11664efea27aee9c864e729b98264abe18842e9b148c231d203fafbb' 
  AND token = 'zBI9qmOV87uL5anu3q8vSUATYHWMUpZZqzBfV7mV6FM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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