SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c839e411f8d185bacb8240a658d44845925ae6fd7ddc2162badf1d97a6c9996' 
  AND token = 'KH+KIQg6OQdrZfKrnvCWRLNaqJjZ7w9JV4a0ot3eMRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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