SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0c9943851dd2956deffb5ba64b428ff17e845b08ac52298a2108bc9b979d5c05' 
  AND token = 'LrBgc8lGxLipXeV/aKvSCdE6ZDJlebkAPngk2EyVjR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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