SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1fd9aadb88fce67eb741f79bee815bad97e1147e13ad0535f195300fd2843aa5' 
  AND token = 'RzDQzW0IRBi2MY/Dlyhp5kHhO6BbAn1Nx6H7VxAGwd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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