SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3c473f91cbbecbdebf575b2fbfd50fcc2bcec8bacd6999bd0111687b04e3421a' 
  AND token = '8tq3mdwWpBL77b+EMy1n8YQ55XS4NrFftLBG8dkbs5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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