SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '351c7e3cbf2a807dd513eb338ce391afc12931b07241cf1295becab1c7480e08' 
  AND token = 'CSp27+Tqrd/3HU1pG9Jvi6R6fSUSnLjHtLGl29r3YVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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