SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '288731b8e041001421cc6e6c84259d7e6d2923b1c14aa70113bb82802160efdb' 
  AND token = 'j+Td5g3FrlQs3CKBC/G/ytz2gOOGvOYHQjwPU0cMTzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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