SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '316015477485afd6d7a0e1bd825267436694c20945380a29509bf552f20deb73' 
  AND token = 'TBWGNaqYcbh2FDevuITtbv/etEZaxUZ03B1C4/2TKfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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