SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7a1176505ae48ed6922729e0aa8706e009237c72e05c8c3730cc1bf8e47fe598' 
  AND token = '6rTSilScwcf8TPObcgmIEWc4PxDi97qh8m0S+SuVpl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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