SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8264f5e45a1599625c121c4cd5018876bfa4640948684722624fa25553a96f14' 
  AND token = 'wCX/Ps9F2NnxybFng4f6JxnnevtOfxF3c/dIKsNNrbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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