SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41c3f4d514065352a62d0b410626eb5efa784d849ec9a13348ba43656497b356' 
  AND token = 'USXOEP89QdmaoAFUSToqPgett8P754noX28voTd4LPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}