SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07e4ea3d26b667e868e68455228fba1f445a21b2847bda38d6304082877953dc' 
  AND token = 'T4/msZhL6W0qthpxl/r3fSXoj7B5lFKY8R4YGDhgkuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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