SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6712219d03b8ebcdc69197bceefbe3bca8124ffff6f311716c0ee30ca3d5d07b' 
  AND token = '7+16yJXhsDERhEKHKU9m9PvUgyjBMxpbhgHAzNS4J1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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