SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7cf52f0e9232e874bf30cd58c33c619d79ad6cdb7f5b298759bf88bae7c83a03' 
  AND token = 'h732Q5bCj6ggbUXWsVQfg5gBSS0RqpT4cj7iMLlyA0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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