SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bdd1a8b40de9af31f22fc14cd3a69fd95a7d382cbc96c77dac797a84c0a972f3' 
  AND token = 'KWOe1cIkOMHIbkuuTEs+UTtnHMJ/229n8KoejojBiCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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