SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '98340c6f049504791fa6bc2e1e5832ca0681b34d53fb206d6a504c073755c426' 
  AND token = '+OnpGWBi/lyfup0PhoIxH+7GgXtB6Xh1ppT1BgbShow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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