SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '08f9f501b97c4fcdedc446efe701c9223238221a98c8a883c43a3f1211e2e319' 
  AND token = 'fwZMCGJWtduCC68KPMZRhEgoz1eOlCsa89qmyT47TrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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