SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72d70e5da11f667fda57fd40c952376e2058241f84187bcbaa0f3066989fde42' 
  AND token = 'R8/Mr3Xz0c7sUCjM3TbL5XvzQBkx1BoF8cwyyPCoDXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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