SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80fa611bc50dce83d1e71b033bcd5e0815ecec262ab2692485f9bee18160a712' 
  AND token = 'f61fTdVAjA4tp1Yd46YBXOffgSEIez32I2Q+42Y4TKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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