SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9719037d47e4ee454148b48c085ba73d0b841d83b1d84fffc45866251bd2a914' 
  AND token = 'C/25LJipZAXXNKW9GaowS9Q9MTZaC/WgSF0JVFBFxyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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