SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e2c82d1cccd6301082ca9e08a202f65026a4d58d086afbbaeefdf1d3e0498d6' 
  AND token = '6fuiwaOnedzP9f4oPidoFfhC5fk+HlcQHx3v3HW1D98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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