SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b5ebf50cc87cb4902a33f46258300c9a7985bf6eafcc1d17e7d94ddf8518de5' 
  AND token = '+Eo/ZbiHAmGfSPFVPvmSFn0pWSvvsErkAkei75clK5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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