SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd2451eaec48a1a6278ff45f743128441f5841d941467c2da9101f39a952beb0c' 
  AND token = 't8lo4saGCCqJ4TEPnCkp/QDlv19wTQKWrTN3D/vY4xE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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